This project will determine the relationship between commonly abused drugs and the probability of aggressive behavior in "normal" human volunteer subjects. Aggressive behavior will be elicited by different frequencies of provocation in controlled laboratory situation. The effects of the following commonly used drugs on human aggressive responding to different frequencies of provocation will be studied: alcohol, d-amphetamine, codeine, diazepam and secobarbital. This project employs a new methodology for the study of human aggressive behavior, which has specific and unique advantages. In the experimental situation, both aggressive and non-aggressive response options are available to the research subject. The aggressive response option is operationally defined (as the presentation of an aversive stimulus to another person) and objectively recorded. The aggressive response is the ostensible subtraction of money from another "person" who is depicted as similarly responding to accumulate money. A non-aggressive response option, i.e., responding for monetary reinforcement is also available to the research subject. Two different frequencies of provocation will be used elicit aggressive responding: high (mean of 20) and low (mean of 5) frequencies of subtractions of accumulated monetary reinforcement from the research subject which is attributed to another "person". Preliminary studies have indicated that this provoking event, i.e., subtractions of money, elicit moderate and high rates of aggressive responding, respectively. This experimental methodology will allow an assessment of the effects of drugs of abuse on different rates of aggressive responding elicited by different frequencies of provocation. The specificity of drug effects on aggressive behavior will be determined by comparing effects on aggressive and non-aggressive responding. This project will provide information on how dosages of drugs commonly consumed by the general public can alter the responses of "normal" human volunteers to aggression-provoking situations. This data will be particularly important in identifying possible relationships between drug usage and violent behavior.